1. Field of the Invention
The present invention relates to an apparatus for producing a coating layer onto a primary lining, which can reliably form a coating layer in a short time on the interior surface of a primary lining composed of segments assembled after propelling a shield tunneling machine.
2. Description of Related Art
Immediately after drilling by propelling a shield tunneling machine, a primary lining is formed by a plurality of segments. For this primary lining, a concrete segment, a composite segment, which, for example, is made of steel and concrete, or a steel segment has been used, and to the inside of this segment, a secondary lining by mortar has been applied. In recent years, with the aim of reducing constructing costs, improving acid resistance, and improving flowability, as shown in, for example, Japanese Unexamined Patent Publication No. Hei-9-72197, a construction method where the secondary lining is omitted by forming a coating of an organic material as an anticorrosion material on the interior surface of segments has been disclosed, and this method has already been used in some area. Such construction methods where the secondary lining is omitted include a method for forming segments by molding concrete and an organic coating on the construction site.
A coating apparatus having a revolving frame for covering the interior surface of segments with an organic coating after completing primary lining is constructed such that, as shown in FIG. 15, to a connecting portion 101 on the tip of a rotation shaft 100 rotated by a drive motor, a balance shaft 102 is attached orthogonally to the rotation shaft 100, a balancer 103 is attached to one end of this balance shaft 102 so that the position is variable, one end of a gun holding shaft 104 slidably attached to the connecting portion 101 of the rotation shaft 100 is fixed to the balancer 103, a spray gun 105 is attached to an end opposite the balancer 103 so as to keep the balance between the balancer 103 and spray gun 105 with respect to the rotation shaft 100. Moreover, by applying a polyurethane resin coating material while rotating the rotation shaft 100 by the drive motor to rotate the spray gun 105, the interior surface of segments is continuously covered with an organic coating.
When segments having a large diameter, for example, approximately 3 to 5 meter are coated by the coating apparatus, the distance between the rotation shaft rotated by the drive motor and balancer becomes large, therefore, rotational torque of the gun holding shaft having the balancer and spray gun becomes large. Accordingly, there exists a drawback in an increase size of the drive motor.
In addition, since the spray gun is rotated approximately at the center of the gun holding shaft having a large rotational torque, it is difficult to keep peripheral velocity at a constant rate when the spray gun is rotating and applying a coating material. Accordingly, there also exists a drawback in that the coating material to be applied to the interior surface of segments fluctuates depending on the spray gun rotating position, thus resulting in a coating of uneven thickness.
The present invention has been made to improve such drawbacks, and it is an object of the present invention to provide an apparatus for producing a coating layer onto a primary lining which can reliably form a coating layer on the interior surface of an underground pipe, a primary lining, etc., in a short time and can also form a coating of a uniform thickness.
An apparatus for producing a coating layer onto a primary lining according to the present invention comprises: a running truck; a revolving ring mechanism; a spray gun mechanism; and a controller, and is characterized in that the running truck has a drive for independent driving control of right and left drive wheels in the forward direction, respectively, and that the revolving ring mechanism has a revolving ring, a revolving ring support frame, and a revolving ring drive mechanism, where the revolving ring is formed by connecting two frames formed in an annular shape by a plurality of connecting shafts in parallel, and the revolving ring support frame has an upper frame and a lower frame, where the upper frame is formed in a T-shape by a support frame and a guide frame provided orthogonally to the end of the support frame, while the lower frame is formed in another T-shape by a support frame and a guide frame provided orthogonally to the end of the support frame, and the support frame of the upper frame is attached to a front surface in a forward direction of the running truck via a centering mechanism, and the support frame of the lower frame is attached to the support frame of the upper frame so as to be shiftable, and on both ends of the respective second guide frames provided are guide rollers to be latched with the inner circumferential surface of the revolving ring, respectively, and the revolving ring drive mechanism has a revolving ring drive motor for rotating a drive transmission mechanism to be engaged with a drive chain or rack provided in an annular shape in the inner circumferential portion of the revolving ring and one or a plurality of brakes attached to the respective guide frames, and that the spray gun mechanism has a spray gun attached to the revolving ring, a rotary joint attached to the running truck, and a supply hose joined to rotational-side pipes of the spray gun and rotary joint, and that the controller rotates the revolving ring at a steady peripheral velocity while a coating material is ejected from the spray gun.
It is desirable that the revolving ring is separable into four parts or six parts.
In addition, it is preferable that the controller rotates the rotary joint in synchronization with a rotation of the revolving ring.
Furthermore, the apparatus for producing a coating layer onto a primary lining comprises: a position detecting sensor for detecting a reference provided on the revolving ring; and a peripheral velocity operating means provided in the controller, for calculating a peripheral velocity of the revolving ring based on an output signal from the position detecting sensor. Moreover, it is desirable the controller makes, after the peripheral velocity of the revolving ring becomes steady, the running truck moves and applies a coating material from the spray gun.
It is desirable that the spray gun is a mixing and colliding type. Preferably, a thermosetting resin such as a polyurea resin coating material and a polyurea resin coating material is applied by the spray gun.